Abstract:
In his paper on the geometrical relations between the Transvaal
Supergroup and the Bushveld Complex, Cawthorn
( 1998) argues that there is ·no need to infer a considerable
period of pre-Rooiberg Group erosion prior to emplacement
of the Bushveld Complex-Rooiberg volcanic rocks. He further
suggests that a significant time interval between the Pretoria
and Rooiberg Groups is now common knowledge, but
that the extent of Pretoria Group erosion before Rooiberg volcanism
is unknown. We note that these two proposals of Cawthorn
(1998) are not readily compatible: a considerable time
gap should in fact promote a reasonable amount of weathering
and erosion between the deposition of the two groups. We
wish to contribute positively to the debate on the relationship·
of the Transvaal and Bushveld rocks by qualifying the proppsals
of Cawthorn (1998) on the basis of the evidence presented
below.
